# Modifying GLFW callbacks

I'm currently using Imgui for the GUI part of my OpenGL/C++ engine with the GLFW binding. The problem is though that this binding has encapsulated the input callbacks in a global .cpp file which makes it impossible to access for other classes. Now I could always use the regular routine to handle input without the callbacks like:

if(glfwGetKey(m_window, GLFW_KEY_A) == GLFW_PRESS)
...


but yet this won't give me the one-to-one mapping like the key callback provides as the conditional code is processed more than once. I have tried using static booleans without success to see if I could overcome the problem by setting the boolean to true when the key is pressed in the callback and then handling the outcome elsewhere. I also know that you can override callbacks with different ones but that would not make any sence in this case.

Does anyone know how to solve this problem?

The problem is though that this binding has encapsulated the input callbacks in a global .cpp file which makes it impossible to access for other classes.

The imgui+GLFW backends have callback exposed in the imgui_impl_glfw_xxx.h file:

void ImGui_ImplGlfwGL3_MouseButtonCallback(GLFWwindow* window, int button, int action, int mods);
void ImGui_ImplGlfwGL3_ScrollCallback(GLFWwindow* window, double xoffset, double yoffset);
void ImGui_ImplGlfwGL3_KeyCallback(GLFWwindow* window, int key, int scancode, int action, int mods);
void ImGui_ImplGlfwGL3_CharCallback(GLFWwindow* window, unsigned int c);


And when you call ImGui_ImplGlfwGL3_Init() you can set install_callbacks=true to install your own callback from where you can call the above functions if you need to.

• Noticed there was actually a comment about this in the header file, but I must have ignored it. But it works as intended. Thanks, Omar! – Riggs Nov 30 '17 at 11:52